The present invention relates generally to a system for monitoring the activities and location of an individual and more particularly to a system for readily determining the presence of an individual in a given environment.
The over-crowded condition of many state penal institutions has led to sentencing or probation requiring the convicted individual to remain in a predetermined location under prescribed conditions. For example, the individual may be continuously confined to a house or apartment for a certain length of time. Alternatively, the individual may be so confined during selected hours of day, such as all non-work hours.
The authorities randomly monitor the activities of the individual to ensure compliance. Any non-compliance normally results in immediate incarceration.
This new sentencing/probation procedure has fostered the development of numerous systems to readily determine whether the individual in question is indeed in compliance with the imposed restrictions. One type of monitoring system is characterized as "telephone continuously signaling"; another is "telephone programmed contact"; and a third is "radio signaling".
In the "telephone continuously signaling" type system, a miniaturized transmitter is strapped to the offender and it broadcasts an encoded signal at regular intervals over a predetermined range. A receiver-dialer, located in the offender's home or apartment, detects the signal from the transmitter and "reports" to a central computer whenever signal detection stops and starts. Periodic checks are also made. The central computer accepts data from the receiver-dialer over a telephone line, compares the data with the offender's time/place restrictions or curfew schedule, and alerts correctional officials to any unauthorized absence.
With the "telephone programmed contact" system, a central computer is programmed to call the offender during the house being monitored randomly and/or at specifically selected times. The computer prepares a report on the results of each call. Strapped to the offender's arm is a wristlet, i.e., a plastic module. When the computer calls, the wristlet is inserted into a verifier box, coupled to the telephone line, to establish that the call is being answered by the offender being monitored.
The "radio signaling" system does not require a telephone interconnection. A small transmitter, known as a link, is worn by the offender. A locator unit, placed in the offender's home or other approved location, receives the signal from the link and relays the information by radio signal to the local area monitor. The local area monitor includes a computer or information mangagement system. This equipment is maintained by a network manager, the leader of a small group of individuals who supervise and offer support to the offender. Each local network handles fifteen to twenty-five offenders.